5 Recombinant human growth hormone

• 1.

  All batches of Met-hGH examined stimulated statural growth to approximately the same extent. The growth rates measured partly exceeded the results obtained in previous studies with pituitary preparations in the same dosage.

• 2.

  Under treatment with SI, i.e. the preparation with the highest amount of ECP, high antibody titres with high binding capacity against GH and ECP were found. With SII all antibody determinations showed much lower titres. With Somatonorm (SIII), in the large majority of cases no antibodies were detectable. The titres registered in a few children were low and the binding capacities were negligible.

• 3.

  The biologically determined somatomedin activity was initially pathologically low. During treatment it rose to supraphysiological levels. Also the radioimmunologically assayed somatomedin and the alkaline phosphatase increased significantly.

• 4.

  At the start of the first series, two patients showed allergic skin reactions which turned out to be caused by the insufficiently purified preparations. Therapy with extractive preparations was free of such side-effects and fully successful. Both of the patients were atopic. A third child who was also allergic developed after 6–9 months the highest antibody titres seen, combined with a high binding capacity. Also, with this boy, treatment was switched over to pit-hGH, with very good results.

• 5.

  Two children with pituitary dwarfism already developed in utero high antibody titres against Met-hGH but not against ECP. For this response, neither the Somatonorm nor its impurities can be implicated. Rather, it is the reaction to GH generally, which the organism recognizes as a foreign protein and thus as an antigen. One of the patients stopped growing after nine months. Likewise, pituitary GH did not lead to any further improvement.